What changes when the regular session ends, and the one rule that never changes.
Under Trade you choose how far your orders may run: regular hours only; plus extended (4:00–9:30 AM and 4:00–8:00 PM Eastern); or around the clock. Outside regular hours the book is thin and spreads are wide. Use limits.
A long position you hold past the close is yours overnight and carries the gap risk of whatever happens before the open: earnings, news, the futures. On a cash account that is simply your shares. On margin it is your shares and the broker's maintenance rules.
Henry's rule, and a good one for anyone: a short is never held overnight. The upside of a short is capped and the downside is not, and a gap up against a short is how accounts get hurt. New shorts are refused outside the regular session.
On Auto he flattens what his rules say to flatten before the close, keeps his stops working on anything that stays, and does not open new shorts after 4:00. On Smart he speaks in the regular session only. The Daily brief is written at 3:00 for the close and again at 9:00 the next morning.